Two-cycle gas-engine.



PATENTED JAN. 7, 1908.

W. A. SALTER. TWO CYCLE GAS ENGINE.

APPLIOATION FILED APR. 18, 1907.

3 SHEETS-SHEET 1.

IN VENTOR WITNESSES:

PATENTED JAN. '7, 1908.

W. A. SALTER. TWO CYCLE GAS ENGINE.

APPLICATION FILED APR.18, 1907.

3 SHEETS-SHEET 2.

IN VEN TOR No. 876,020. PATENTBD JAN. 7, 1908.

W. A. SALTBR. TWO CYCLE GAS ENGINE.

APPLICATION IILIID APR 18, 1907. I

3 SHEETS-SHEET 3.

IN VENTOR of which. the following is a NITED STATES WILLIAM A. SALTER, OF CEDAR POINT, KANSAS.

TWO-CYCLE GAS-ENGINE.

Specification of Letters Patent.

Patented Jan. 7, 190 8.

Application filed April 18 1907. Serial No. 368,896.

To all whom it may concern:

Be it known that 1, WILLIAM A. SALTER, a citizen of the United States, residing at Cedar Point, in the county of Chase and State of Kansas, have invented new and useful Improvements in 'lwo-CycleGas-Engines,

specification. The object of this invention is to enable the utilization of an explosive gas mixture,-- in what is known as an internal combustion or explosion gas engine, with materially greater economy in the amount of gas consumed, and higher relative efiiciency in the amount of power produced therefrom, with a greater range of speeds at which the engine will workand produce economical power, by maintaininga higher purity or nearer perfectmixture, of the power as charge in the Com-' busti on chamber on all different speeds of the engine, than has heretofore been attained.

A further object is to provide an engine, which for a given size or weight shall produce the greatest amount of power.

To attain this end, generally speaking, my invention consists of a combustion chamber and a compression chamber having aconnecting gas passage or passag'es of large area, so as to allow of quick transfer of power gas even under light compression, a piston, and an exhaust valve in the combustion. chamber mechanically operated and capable of adjust ment and control so that it will open and close at different points or periods relative to the revolutions of the crank shaft and the location of the piston in its reciprocating motions. Y

My invention further consists, in an engine as above described having a variably timed exhaust valve, and having a throttle in the inlet power gas passage, .so that the volume of the successive power gas charges entering the compression chamber can be varied at r the will of the operator.

My invention furtherconsistain an engine as above described, having an exhaust valve variably timed, a throttle in'the inlet gas passage, and means for operative control and adjustmentgof the exhaust valve and gas throttle As my invention contemplates the application of these improvements to the most highly organized gas engines of the present day, I do not confine myself to the details 0t construction 1 and organization herein. shown, but when specifying a particplar construction or organization intend to include well known equivalents therefor.

fully set forth.

The characteristic defect of the gas engine of the present day, is the difliculty of maintaining a perfect mixture of gas (consisting each revolution-of the crank sha the piston oes not approach closely to the cylinder head, and there is always remaining in the combustion chamber, coming fresh charge of power gas, as many cubic inches of burned exhaust gases as there are cubic inches of space between the cylinder head and the head of. the piston at its extreme point head, this being called the clearance space. In the two cycle engine as 'at present in general use and practice, this, objection is present to a greater degreethan in-the -fourcycle engine, and this type of engine is also very inflexible, having only one speed at which it will attain highest/working power and efficiency, due to the relative ratio of the c'ylindercapacity and the clearances of the inlet and exhaustports. The two cycle engine is generally regarded as bein good for what is one speed, or what is very c ose to at w 'ch the engine .is capable of being driven. When it is undertaken to reduce bythrottling or reducing the quantity'of .fresh gas entering intothe combustion chamber, the residue or exhaust gases isso large in proportion to the fresh charge, (to the impairment of the explosive charge and the useless compression of this burned dead gas constituting a valve, adjustably controllable, and transfer ports and gas passages, with'variable' comto dilute'the in-' of travel toward the cylinder brake on the working of this type of engine,) I

The improvement claimed is hereinafter In-gas en ines as at pres nt in general use,

one s eed, and that one near the maximum remaining burned I pression in the compression chamber by varying the volume of working power gas admitted to that chamber.

Taking as a starting point, that point in the revolution of the crankshaft where the piston has reached its highest point of travel, that is, the point nearest the cylinder head, the exhaust valve istimed to open at approximately 125 of the crank shafts revoution from that point, on the working stroke of the piston. When the engine is working at its greatest power, and receiving a charge of gas nearest e ual in vohnne .to its piston displacement, the exhaust valve is' then timed to close at a point where the piston.

has moved backward on its compression stroke, equal to the clearance space in the engine. The fresh charge of gas injected in front of the piston, then. crowds the burned exhaust gas forward and the exhaust gas roducts are totally expelled (if there has been no intermingling of the old and new charge) the exhaust valve closing at the 4 roper moment to catch the full char e of es pure gas; which is then compress'e and fired or exploded the working stroke. Or

when the inlet gas passage leading into the compression chamber is throttled and a charge of gas smaller than the volume of the iston displacement enters the compression an combustion chamber, the exhaust valve held open thenor. suspended from its seat for a longer time during the compression stroke of the piston, and just closes as the fresh gas in front of the piston pushes out (and expels) the exhausted burned gas product in front of it,the

valve thus catching and the piston compressing the. smaller fresh charge of gas for firing and worldngstroke, but in this latter case, it is obvious that as thevolume of the gas charge is less than where a charge is admitted, therefore with the smaller charge the 001m pression in the combustion chamber is less than where a full charge is used, resulting in a less powerful explosion, and a slower burnin combustion so that the crank shaft revo ves at a slower working speed than where the full charge of power gas is used. The same cycle of operations result in all the graduated adjustments of which the engine is capable, with pro ortionate variations be tween the timin .o the exhaust valve and the volume of e workinggas charge, for.

- economical operation; "It is obvious, how- 'terially changingthe power which it usually ever, that the engine will work without ma,-

has on the slow speed, ifa large charge of gas 'is admitted to the combustion chamber and only result fresh gas char then be expelledv with the burned e aust gases of the preceding I charge and wasted," the engine only ca tchmg,

compressingand'firing the usualgsmaii sized eing inthaticase, that part ofthe.

its reciprocations forming t between the combustion; chamber '1, and .the compression chamberZ. These various charge of gas for that working adjustment of the exhaust valve.

Assuming the engine to be a vertical one, in the accompanying drawings, Figure 1 is a vertical (central) transverse section through a gas engine embodying my invention, but not showing the gas inlet throttle. Fig. 2 is a drawing showing an engine of this type and embodying my invention, having two cylinders arranged vertically, the right hand one tion, of the multiple faced cam and the camguide with which it engages. Fig. 5 is a side view in elevation of the gas throttle placed in the gas inlet to the compression chamber, and its connections. Fig. 6 shows a modified connection between the throttle-operating rod and the cam-operating lever.

Inthe practice of my invention, I provide a cylinder 8, which is bored out truly from its lower end to the head thereof and in the center of thehead is also bored to provide for the admission and fitting of the exhaust valve cage 7. The cylinder 8 is also provided at'its lower end with flanges and bolt holes for fastening and fitting it to the upper part of the crank case 9. This cylinder 8 is also cast with double walls, provided in its upper portion with an annular cavity 40, through which water or other liquid is circulated for cooling purposes, and in its lower portion there is a gas passage 3 for the transferring of the power gas from the compression chamber 2 to the combustion chamber 1. This as assa e 3 o ens into the combustionchamber 1, through a series of openings or ports 3' preferably entirely circling the cyl inder wall, the area of said ports being approximately four fifths that of the-exhaust Valve and separated fromeach other byf The lower end bridges of the cylinder wall. of this gas passage may entereither directly into the compression chamber, or else work in connection with a series of ports, preferably, having a total or greater area than the ports 3; these lower ports c'o-inciding with similar ports in the side of the piston, as ports 5, when the piston is at the end of its working stroke. I tains the piston 5, carrying suitable packin rings to prevent the escape of-gas'past it, an

being attached to the crank shaft 21; through the means of the connecting1 parts are so assembled and adjusted that the The cylinder further 'coni rod-22, and in e working: part cap screws.

piston in its lowest point of travel uncovers a gas tight part of the compression chamber,

and also an oil pan for retaining a lubricating element. It also in conjunction with the u per part of the crank case 9, as shown in ig. 1 and Fig.2, forms the bearings 39, 39, for the camshaft 18, while the bearings 38, 38, for the slide bar 23 are formed in a part of the upper half of the crank case 9.

' The exhaust valve cage? is fitted in the head of the cylinder 8 and held in lace by The valve 6 works in t e valve cage by a valve stem 35 passing through a suitable hole bored for its reception. The valve stem carries a head 36 on its up er end, and a helical spring 17 interposed etween the valve stem head and the valve cage 7, securely holds the valve 6. to its seat.-

its lower end to the rocking l' '33 for the purpose of holding it in proper working positi'on, and it also carries at its lower end a cam wheel 15 working in engagement with the cam 12.

The crank shaft 21 carries a spur gear 20 working in engagement with another spur gear 19 of the same diameter which is secured to the cam shaft 18, which it causes to rotate at the same speed as the crank shaft 21. The cam shaft 18 isround in form throughout the greater part of its length,

but at the pointswhere it carries the cam 12 it is s uare in section for alength greater than t e length of the cam 12, and thus while it provides for the positive rotation of the cam 12 which it bears with it, the cam is at the same time capable of being moved axially along the camshaft. The cam 12 ovides for the variable timing of the exhaust valve in its closing, and is made with a square hole axially throughout its length corres onding to the squared portion of the cam s aft 18 on which it seats.

The cam 12 has at one end an annular channel or roove 26in which engages the tork 24. T cam 12' is. also' of a reater 1e th thanthe cam wheel 15, and might be ed a plurality of cams in one, comprising a series of steps out inits working face and made of various. lengths of the arc, so that the path of travel. of the cam wheel 15 across revolution of the crank shaft.

the cam 12 at its short arc end is of a comparatively short duration holding the exhaust valve open-for about 105 of the full But the cam 12 is moved along the cam shaft 18 until its greatest length of arc portion is brought into engagement with the cam wheel '15, it causes the cam wheel 15 to be raised and the exhaust valve to be held open for approximately 180 of the revolution of the crank shaft. The intermediate arcs and steps in the cam 12 are variations, graduations and proportions between the two extreme adjustments, and all may be varied atthe will of the constructor.

The cam 12 is moved for its adjustments -b the fork 24, mounted on the slide bar 23 w ch is carried in bearings 38, 38, on the engine case. i The fork 24 1s held in position on the slide bar 23 by the collars 37, 37, and the helical spring 25 interposed between the cam and the collar 37. In the case ofa single cylinder engine, it is not necessary to use this spring 25, but where there is a num-- ber of cylinders in the engine, should one cam wheel 15 at the time of throwing or moving the slide bar.23 to the left be against one of theshoulders of a cam 12, it allows the bar to be operated and as soon as the revolution of the cam shaft 18 revolves sufficiently to disenga e that cam wheel, the spring then brings that cam into proper osltion .or adjustment with the others. The slide bar 23 is operated by the controlling lever 28 pivoted to an arm 27 secured to the engine. i

The gas inlet passage 29 opens through a port'into the com ression chamber 2, and is opened when the ower ed e of the piston 5' rises above it and is closedfiay the downward movement of said piston. It is. connected with the outside gas piping 30 leadin to the gas throttle 31 and vaporizing cha n er 31. The gas throttle 31 may be,of any well known construction of the art, and is connected to the operating lever 28 by the connecting rod 32. .In the construction shown in Fig. 5 it is contemplated that movement of the rod 32 and throttle to the left opens the throttle wider and increases the admission of gas, and movement to the right closes the same and restricts the admission of power as. r

Prefera ly, the connections between the rod 32; and the controlling lever 28 are such that they are operative co-jointly, the valve closin earlier with the wider opening of the throttle and vice versa. But they are capable of adjustment so that each can be operated independently ifdesired, as it does not change the spirit of this invention or the economy or efficiency of the working of the engine where they areindependently con-. trolled. Such a construction is shown in Fig. 6, where the rod 32 is provided witha plurality of teeth 33 adapted to engage with the lower end of the loop 34 on the lever 28 through which saidrod passes. A handle 35 on the end of the rod enables the attendant to lift it and shift the lever to a new position of engagement when desired. Such a movement of the lever will slide the cam along the the same results in power and efficiency,

owing to differences in temperature, atmosphere conditions, and variations in altitude, which tend to vary the ratios of expansion of thefresh cold 'mixture when admitted into the hot combustion chamber. In order, therefore, to secure perfect efficiency under all conditions, a certain latitude of adjustment between the operation of the throttle and the exhaust vala e is necessary. It will be noted that whenever the controlling lever is moved to the left, in Fig. 5, it advances the time of theclosing of the exhaust valve, so as to utilize a larger working charge, and at the same tiinethe throttle is correspondinglyopened to provide the in creased charge, and vice versa. Ignition is preferably accomplished by electrical means, either by the jump spark method, or make and break mechanism.

In operation, the upward stroke of the )isto'ii draws into the compression chamber 2 by vacuous induction, :1. charge of power gas or vapor and air, which is compressed on the downwardstroke of the piston, and on the piston passing the ports 3 of. the open gas passage 3, this charge then rushes into the combustion chamber 1, and is compressed and exploded, a fresh charge of. gas at the same time entering the compression chamber for the next working stroke, or explosion.

I claim, as my invention and desire to secure by Letters Patent: v v

.1. In gas'engine,the combination of a. cylinder having a combustion chamber and a i compression chamber with a communicating passage between them adapted to be opened y a piston at the'endof its downward stroke and closed near the beginning of its upward stroke, a source of supply opening into the compression chamber having a throttle therein, and an exhaust valve in the combustion chamber variably timed opcratively and adjustably controllable.

2. In a two cycle gas engine, the combina- 1 tion of a combustion chamber and a com oression chamber with a communicating pasa piston at the end of its working stroke, a source of supply opening into the compression chamber, an exhaust valve in the combustion chamber timed to open before the opening of the passages between the combustion and compression chambers, means for varying the volume of the ower gas admitted to the compression 0 amber, and means for varying the timing of the closing of the exhaust valve.-

3. In a two cycle gas engine, the combination of a cylinder having a 'combustion chamber and a compression chamber with a communicating passage between them having a series of ports entirely encircling the combustion chamber, and adapted to be opened by a piston at the end of its working stroke, a supply port to the compression chamber mechanically opened during the pistons upward stroke and closed at or near the' beginning of the pistons downward stroke, an exhaustvalve in'the combustion chamber timed to open before the opening of the inlet ports to thecombustion chamber,

and means for variably timingits closing.

points.

4. In a two cycle gas engine, the combination of a cylinder having a combustion chamber and a compression chamber with a communicating gas passage between themadapted to be opened by a piston at the end of its downward stroke, a supply port opening into the compression chamber and adapted to be opened by the piston during its upward stroke, and a variably timed exhaust valve in the combustion chamber mechanically operated. n

I 5. In a two cycle gas engine, the-combination of a combustion chamber and a compression chamber with a communicating passage between them adapted to be opened by a piston at the end of its downward stroke, a supply port opening into the compression chamber-and adapted to be opened by the piston during its upward stroke, an exhaust valve in the combustion chamber timed toopen before the opening of the passage between the combustion chamber and compression chamber and variably timed in its closing points, means for varying the volume of the power gas admitted to the compression chamber, and means for'controlling the timing of the closing of the exhaust valve. l v

6. In a gas engine, the combination of a cylinder having ja "coiiibustion chamber and a compression chamber with a communicating passage between themadapted to be opened by a pistonatj'tlieend-of its downward stroke and clo'sed'n'ear the beginningof its upward stroke, a supply port 0 ening into the compression chamber and a apted I to be opened by the piston during its upward stroke and closed during its downward stroke,

sage between them adapted to be opened by i an'exhaust valve in the combustion chamj ber, a* crank shaft, a cam shaft working in engagement with the crank shaft and having mounted thereon a cam consisting of a number of working arcs of different lengths, said cam rotating in unison with the crank shaft and adapted to be moved axially along its seat for variably operating the exhaust valve and means for adjusting the-cam.

7. In a gas engine, the combination of a cylinder having a combustion chamber and a compression chamber with a communicating passage between them adapted to be opened by a piston at the end of its downward stroke, a supply port opening into the compression cham er and adapted to be opened by the piston during its upward stroke and having a throttle connected therewith, an exhaust valve in the combustion chamber, a crank shaft, a cam shaft working in engagement with the crank shaft and having mounted thereon a cam consisting of a number of working arcs of different lengths, said cam rotating in unison with the crank shaft and adapted to be moved axially along its seat for variably operating the exhaust valve, means for adjusting the cam, and means for adjustment and operative control of the exhaust valve and throttle co-jointly.

8. In a gas engine, the combination of a cylinder having a combustion chamber and a compression chamber with a communicating passage between them adapted to be opened by a piston at the end of its down- I ward stroke, a supply port opening into the compression chamber and adapted to be opened by the piston during its upward stroke, a throttle in the passage conveying gas to the supply port, l the combustion chamber variably timed 5 operatively, means for controlling the timing oi the exhaust valve, and means for ad ustlng the throttle.

9. In a gas engine, combustion chamber having an exhaust valve therein variably timed operatively, a cam operating the exhaust valve and mounted so as to be movable along its seat, controlling means for adjusting the position of the cam, and yielding connection between the controlling means and the cam.

10. In a gas engine, the combination of a combustion chamber having a variably timed exhaust valve therein, a cam operating the exhaust valve and mounted so as to be movable along its seat, a movable controlling rod having annular collars secured thereto with a spring interposed between two collars, and a cam guide mounted on the con trolling rod between one of the collars and the spring and engaging with the cam.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses 1 WILLIAM A. SALTER.

\Vitnesses.

M. A. SALTER,

JOHN B. HANNA.

the combination of a an exhaust valve in 

